My father was of the generation that you see in old black and white movies where the men all wore suits and felt hats. I, and my generation, stopped wearing formal hats. The only time I wear a hat is to keep my head warm. After many decades I have finally figured out why we stopped wearing hats. My father and his generation rode in open touring cars, like the Model T Ford below, until the 1930s. There was a top to keep the rain off, and though there were side curtains, they were seldom used. These cars were cold to ride in. Hence, the hats. I grew up with enclosed sedans and needed no hat.
As a result we have raised a generation of men that do not know the proper etiquette of wearing a hat. They do not know that you remove your hat as a sign of respect for the elderly, or for ladies, or when you enter someone’s house; especially the Lord’s House.
But, as always, the answer is found in God’s Word.
Therefore, do not wear your hat in the House of the Lord, much less pray with your hat on.
Also in chapter 11 the Apostle Paul says that a woman’s head should be covered, but clarifies by going on to say that a woman’s long hair is to her glory and is given to her as a covering. (11:15)
On the subject of trends, here is another statement by the Lord.
We can always count on the inerrant, timeless Word of God for direction. May his name be praised forever.